The ECA via power relay, provides power to all the injectors. When the ECA receives an RPM signal it provides the ground signal for the injectors to fire.

All the injectors should have power at them with the key on. That you can verify with a meter, should be battery voltage (12 volts).
That is one reason I suggested checking the fuses , all of them , we don't know if something was altered (fuses/ECA) with jumping the relays.

 

I will check all of this tonight.

One other question- When I turn the key to the on position, shouldn't the fuel pump stop pumping after a couple of seconds? Cause right now it pumps non-stop with key on and stops with key off. I believe the fuel pressure regulator is fine and the system tests at about 45psi.

Also Hanky, thanks so much! This information is invaluable to me and my daughter.

 

Yes it should, if it receives no RPM signal.

What we need to verify is,,,,,,,,,,,,,the fuel pump relay coil is either getting a constant ground from the ECA or something is causing the fuel pump relay to stay energized without an RPM signal.
As I recall the power relay and the fuel pump relay are the same part # and are interchangeable.

 

Where does the RPM signal come from and I wonder how I can test that? The van does not have a tachometer.

 

It originates from the pick up coil in the dist. goes to the ign module and the ECM.

 

Okay so I pulled the 2 pin electrical plug off of one fuel injector and with key on both pins get 12v positive. Neither are a ground! Is that right? I assumed one would be ground and one would be positive, but they're both positive and they're both on permanently with key on.

The ground on the fuel pump relay is weak and sometimes only shows 6 or 7 volts. It is on permanently with the key on. That's why I added a secondary ground that I made, so it would see the full 12v. I explained why in my original post in this thread but basically the relay was buzzing nonstop when key was on and replacing it did not change anything:


They are similar, but don't fit in the same connectors. I replaced the fuel pump relay and I bench tested the other and they both seem to work just fine.

Is there an overall wiring diagram for this vehicle somewhere? Online possibly? I would by a haynes manual or something if I have to.

 

The first thing I noticed was both injector terminals when unplugged. Only one wire should have power with the key on. If both do, there is a problem with the ground to the injector(S). There is a short to power in that part of the circuit. What you can do is, unscrew the bolt that holds the multiple pin connector to the ECA and check if one or both still have power with the key on. If not there is a problem with either possible corrosion at that multiple pin connector at the ECA or there is a problem with the ECA, which then would need to be replaced.

Not sure if a Haynes manual will be that much help.

Again if memory serves , the power relay and fuel pump relay are the same type and there should be no problem switching those relays, the plugs should accept either relay. There may be a problem there too.

The plug to the ECA should be located on the passenger side of the firewall, down low where it can be a pain to access. Sometimes the battery had to be removed to gain access.

 

Okay so I still get battery + at both pins of the connectors leading to fuel injector when the key is on or while trying to crank engine. Nothing when the key is off. This is when the ECM (or ECA as you call it) is installed or disconnected. I disconnected the bolt holding the ECM 60 pin connector and pulled it off entirely, ECM totally removed from vehicle. The fuel pump also runs without the ECM.

So now I am totally at a loss for where the fuel injector wires are going and they immediately go into bundles of wires I cannot reach or separate easily.

I really wish I had a full on diagram of the wiring on this vehicle. I am decent with electrical stuff and from that could hopefully figure it out.

Haynes, Chilton, All Data DIY subscription, or factory service manual? Can any of this help and is any of it low cost or found for free? I REALLY REALLY would feel better with an accurate and detailed wiring diagram. I understand some of this may have been altered by previous owners, but it would still help me I think.

 

We need to find out why the fuel pump relay is getting a ground to pull in the relay.
If you have the tools ,connectors and terminals you could always cut the wire that is supposed to provide the ground and work back to see why it is grounded and where.
I have to check if I still have a diagram for your vehicle. Until then, you might need to do color tracing of the wire back to the computer plug.
I realize this i not much help at this point.

 

Rereading the earlier posts, I read where you installed a constant ground to the fuel pump relay. That has to come off ! !
ONLY THE ECA IS SUPPOSED TO PROVIDE THE GROUND.

AFTER YOU CORRECT THAT , LET US KNOW WHAT YOU HAVE.